Importance of gel spinning for uhmwpe fiber morphology and mechanical performance

We present a novel gel-spinning apparatus to determine the effect of the as-spun crystalline structure on the drawability and final tensile properties of ultra-high molecular weight polyethylene (UHMWPE) fibers. From SAXS measurements, we show that the extensional flow field applied during spinning significantly affects the starting crystalline morphology, from randomly oriented lamellae to lamellae oriented in the flow direction to the start of shish-kebab. The well-defined as-spun fibers are drawn using the VADER 1000 in fiber mode, which allows for direct monitoring of strain, strain-rate, and stress in-situ during drawing. The VADER 1000 also allows for direct quantification of modulus and strength of fibers at low, intermediate, and high draw-ratios.